KEY AND CHARACTERS 221 



Form of the amphids a distinct spiral; spinneret present 



Winged; 'f ; striae coarse, plain; spinneret heavily cutinized; cephalic setae 4 Cynura 46 



Wings none; female sexual organs double; striae fine, plain 



Ovaries reflexed; no lips; pharynx none or nearly obsolete; osellate (lonema) 9 



Ovaries outstretched, -f-; cephalic setae 4; pharynx tubular, narrow 

 Spiral amphid of one wind, somewhat hook-form; ocellate; pharynx obscure. .Coinonema 42 



Spiral amphid of several winds; not ocellate; pharynx well developed Xinema 47 



Form of the amphids circular or elliptical 

 Striae interrupted on the lateral fields; lateral wings present; spinneret present 



Female organs single, -f; amphids 2 concentric circles; setae in groups of 3 (Omicronema) 50 



Female organs double, 'f; amphids not 2 concentric circles; setae not in groups 



Spinneret heavily cutinized; cephalic setae 4; amphids really spiral (Cynura) 46 



Spinneret simple, normal; cephalic setae 10; amphids small, elliptical (Anoncholaimus) 93 



Striae not interrupted on the lateral fields 

 Spinneret none; striae fine, plain 



Ovaries 2, -f-; setae 4; amphids more or less deltoid; phar. irregularly napiform. . (Didelta) 33 

 Ovary 1, outstretched; amphids not deltoid 



Amphids very small; ceph. setae in 3 circlets of 6; f-; cuticle reticulated. . . .Halanonchus 51 

 Amphids large; setae 10, with 6 subcephalic; -f; lips with digitate processes 



Intestinal cells with crystals; caudal setae none; amphids not raised (CrystaUonema) 67 



Intest. cells without crystals; amphids raised; about 10 thorn-like caudal setae . (Zanema) 68 

 Spinneret present 



Ceph. setae in 3s; coarse, transverse striae resolvable into elongated elements. .Omicronema 50 

 Cephalic setae not in groups; striae, if resolvable, not into elongated elements 

 Buccal cavity more or less obscure, easily overlooked; wings none 



Ceph. setae 4, 3-jointed; lips confluent; amphid i wide as trunc. head, closed. Rhadinema 37 

 Cephalic setae 6 or more, minute or papilloid 



Lips none; amphid (?) unclosed behind, minute; head rounded; -f (Litotes) 1 



Lips soft and rather obscure; amphid fairly well developed, closed (Zygonemella) 26 



Buccal cavity obvious; setae only in Halinema long, then twice as long as head is wide 

 Ocelli present; ceph. cuticle thick; head distinctly conoid; minute onchia (?) .Isonemella 109 

 Ocelli none; cephalic cuticle not thickened; head not distinctly conoid; no onchia 



Ovaries two, ' f ' ; striae fine, plain ; onchia vestigial ; 6 cervical glands Anoncholaimus 93 



Ovary one, -f ; striae usually rather coarse; pharynx quite unarmed 



Head end diminished to form a sort of beak; pharynx tubular Rhynchonema 43 



Head end not diminished to form a beak; pharynx not tubular 



Setae and amphids large; phar. shorter than head is wide; caudal setae pres. . Halinema 52 

 Setae and amphids medium size ; lips conoid , tips with minute ' ' claws' ' . (Dactylaimus) 29 

 Wall of the pharynx armed with teeth or onchia 



Armature spear-like; caudal glands and spinneret typically (usually) absent 

 Spear with a bulbous base; striae fine, plain 



Oesophagus plain, faintly cephaloboid; -f ; cuticle with wings Aphelenchulus 81 



Oeosphagus with a posterior bulb or swelling; cuticle without wings 

 Amphids ellip., well devel. internally; ' f ' ; spear faint; lips 6, faint, unipapillate. Triplonchium 80 



Amphids linear, transverse; oesophagus dorylaimoid; f'; no labial papillae Doryllium 84 



Spear plain, i.e., without bulbous base; striae fine, nearly always plain 

 Oesophagus plain, i.e. without median or posterior swelling; spinneret present 

 Amphids 0; -f ; cephalic setae 0; head truncate; lip-region set off; spear small " prod" . lotonchium 82 

 Amphids present; lip-region not set off 



Amphids symmetrical to one line only; setae 10; pharynx long; spear toothlike (Catalaimus) 89 

 Amphids spiral, sometimes faint; 'f; striae unaltered laterally; cephalic setae 4 

 Ocellate; amphids labial; "spear" slender in nar. phar.; lips and papillae none.Onchulella 87 



Ocelli none; lips 3, papillate; "spear" toothlike, in an open cavity (Digitonchus) 95 



Oesophagus with posterior swelling which sometimes occupies 5 the neck 



Spinneret present ; amphids spiral (?) ; eyes present ; ceph . setae 4 ; lipless Onchium 83 



Spinneret none; striae fine 

 Amphids 0; -f ; no ceph. setae; head truncate; lip-region set off; speara small prod. lotonchium 82 



The amp^Tds "lliptical ; spear-tip bent ; ' f ; lips 6, bipapillate Campydora 88 



The amphids symmetrical to one line only; lips set off by constriction 



Female organs double, f ; spear long and very slender; pre-rectum very long. . .Leptonchus 85 

 Female organ single, f; spear short, not slender; pre-rectum short 



Posterior oesophageal swelling short, not set off by constriction in front. . . . (Doryllium) 

 Posterior oesophageal swelling long, set off by constriction from previous part. Axonchium t 



Tooth one (for alternative see top Page 223: "Teeth two" 



Oesophagus with a median or posterior bulb or swelling, or both (for alternative see Page 222) 

 Amphids none or unknown, or so inconspicuous or faint as to be difficult to see 

 Striae fine, plain; spinneret none; 'f ; naked; lips 6, bipapillate; spear bent at apex. Campydora t 

 Striae altered on the lateral fields 

 Wingless; spinneret present; onchulus with large dorsal muscle; setae small. . . . (lotadorus) 115 



s'piMerefpresent; striae coarse, resolvable; 'f ; lips retractile; setae 4 (Ptycholaimellus) 116 



Spinneret absent; striae fine, plain; ' f ; lips not retractile, naked; spear bent. . (Campydora) 



sTnicturfofamphids more or less irreg., often symmetrical to one line (for alternative see Page 222) 

 Contour of the amphids not linear; spinneret present 



Striae altered laterally; onchus small, well forward; setae obscure; lips 12 lotadorus 115 



Striae unaltered laterally; 'f , Qa 



Setae fasciculate; cuticle thick; lips faint jiantnoaora 



Setae not fasciculate; cuticle notthick _......... Bolbella 



Contour of the amphids linear; appearing as transverse slits opposite the pharynx 

 Striae altered laterally; spinneret present; 'f; striae coarse, resolvable 



